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From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>, Peter Anvin <hpa@zytor.com>,
	Jiang Liu <jiang.liu@linux.intel.com>,
	Joe Lawrence <joe.lawrence@stratus.com>,
	Jeremiah Mahler <jmmahler@gmail.com>,
	Borislav Petkov <bp@alien8.de>,
	andy.shevchenko@gmail.com, Guenter Roeck <linux@roeck-us.net>
Subject: [patch 04/14] x86/irq: Reorganize the return path in assign_irq_vector
Date: Thu, 31 Dec 2015 16:30:46 -0000	[thread overview]
Message-ID: <20151231160106.403491024@linutronix.de> (raw)
In-Reply-To: <20151231155849.772553760@linutronix.de>

[-- Attachment #1: x86-irq--Reorganize-return-path-in-assign_irq_vector.patch --]
[-- Type: text/plain, Size: 2208 bytes --]

Use an explicit goto for the cases where we have success in the search/update
and return -ENOSPC if the search loop ends due to no space.

Preparatory patch for fixes. No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 arch/x86/kernel/apic/vector.c |   22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

--- a/arch/x86/kernel/apic/vector.c
+++ b/arch/x86/kernel/apic/vector.c
@@ -116,13 +116,12 @@ static int __assign_irq_vector(int irq,
 	 */
 	static int current_vector = FIRST_EXTERNAL_VECTOR + VECTOR_OFFSET_START;
 	static int current_offset = VECTOR_OFFSET_START % 16;
-	int cpu, err;
+	int cpu;
 
 	if (d->move_in_progress)
 		return -EBUSY;
 
 	/* Only try and allocate irqs on cpus that are present */
-	err = -ENOSPC;
 	cpumask_clear(d->old_domain);
 	cpumask_clear(searched_cpumask);
 	cpu = cpumask_first_and(mask, cpu_online_mask);
@@ -132,9 +131,8 @@ static int __assign_irq_vector(int irq,
 		apic->vector_allocation_domain(cpu, vector_cpumask, mask);
 
 		if (cpumask_subset(vector_cpumask, d->domain)) {
-			err = 0;
 			if (cpumask_equal(vector_cpumask, d->domain))
-				break;
+				goto success;
 			/*
 			 * New cpumask using the vector is a proper subset of
 			 * the current in use mask. So cleanup the vector
@@ -145,7 +143,7 @@ static int __assign_irq_vector(int irq,
 			d->move_in_progress =
 			   cpumask_intersects(d->old_domain, cpu_online_mask);
 			cpumask_and(d->domain, d->domain, vector_cpumask);
-			break;
+			goto success;
 		}
 
 		vector = current_vector;
@@ -185,17 +183,13 @@ static int __assign_irq_vector(int irq,
 			per_cpu(vector_irq, new_cpu)[vector] = irq_to_desc(irq);
 		d->cfg.vector = vector;
 		cpumask_copy(d->domain, vector_cpumask);
-		err = 0;
-		break;
+		goto success;
 	}
+	return -ENOSPC;
 
-	if (!err) {
-		/* cache destination APIC IDs into cfg->dest_apicid */
-		err = apic->cpu_mask_to_apicid_and(mask, d->domain,
-						   &d->cfg.dest_apicid);
-	}
-
-	return err;
+success:
+	/* cache destination APIC IDs into cfg->dest_apicid */
+	return apic->cpu_mask_to_apicid_and(mask, d->domain, &d->cfg.dest_apicid);
 }
 
 static int assign_irq_vector(int irq, struct apic_chip_data *data,



  parent reply	other threads:[~2015-12-31 16:31 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-12-31 16:30 [patch 00/14] x86/irq: Plug various vector cleanup races Thomas Gleixner
2015-12-31 16:30 ` [patch 01/14] x86/irq: Fix a race in x86_vector_free_irqs() Thomas Gleixner
2015-12-31 16:30 ` [patch 02/14] x86/irq: Validate that irq descriptor is still active Thomas Gleixner
2016-01-16 21:16   ` [tip:x86/urgent] " tip-bot for Thomas Gleixner
2015-12-31 16:30 ` [patch 03/14] x86/irq: Do not use apic_chip_data.old_domain as temporary buffer Thomas Gleixner
2015-12-31 16:30 ` Thomas Gleixner [this message]
2016-01-16 21:17   ` [tip:x86/urgent] x86/irq: Reorganize the return path in assign_irq_vector tip-bot for Thomas Gleixner
2015-12-31 16:30 ` [patch 05/14] x86/irq: Reorganize the search " Thomas Gleixner
2016-01-16 21:17   ` [tip:x86/urgent] " tip-bot for Thomas Gleixner
2015-12-31 16:30 ` [patch 06/14] x86/irq: Check vector allocation early Thomas Gleixner
2016-01-16 21:17   ` [tip:x86/urgent] " tip-bot for Thomas Gleixner
2015-12-31 16:30 ` [patch 07/14] x86/irq: Copy vectormask instead of an AND operation Thomas Gleixner
2016-01-16 21:18   ` [tip:x86/urgent] " tip-bot for Thomas Gleixner
2015-12-31 16:30 ` [patch 08/14] x86/irq: Get rid of code duplication Thomas Gleixner
2016-01-16 21:18   ` [tip:x86/urgent] " tip-bot for Thomas Gleixner
2015-12-31 16:30 ` [patch 09/14] x86/irq: Remove offline cpus from vector cleanup Thomas Gleixner
2016-01-16 21:18   ` [tip:x86/urgent] " tip-bot for Thomas Gleixner
2015-12-31 16:30 ` [patch 10/14] x86/irq: Clear move_in_progress before sending cleanup IPI Thomas Gleixner
2016-01-16 21:19   ` [tip:x86/urgent] " tip-bot for Thomas Gleixner
2015-12-31 16:30 ` [patch 11/14] x86/irq: Remove the cpumask allocation from send_cleanup_vector() Thomas Gleixner
2016-01-16 21:19   ` [tip:x86/urgent] " tip-bot for Thomas Gleixner
2015-12-31 16:30 ` [patch 12/14] x86/irq: Remove outgoing CPU from vector cleanup mask Thomas Gleixner
2016-01-16 21:19   ` [tip:x86/urgent] " tip-bot for Thomas Gleixner
2015-12-31 16:30 ` [patch 13/14] x86/irq: Call irq_force_move_complete with irq descriptor Thomas Gleixner
2016-01-16 21:20   ` [tip:x86/urgent] " tip-bot for Thomas Gleixner
2015-12-31 16:30 ` [patch 14/14] x86/irq: Plug vector cleanup race Thomas Gleixner
2016-01-16 21:20   ` [tip:x86/urgent] " tip-bot for Thomas Gleixner
2016-01-04 15:35 ` [patch 00/14] x86/irq: Plug various vector cleanup races Joe Lawrence
2016-01-14  8:24   ` Thomas Gleixner
2016-01-14 10:33     ` Borislav Petkov
2016-01-16 21:37       ` Joe Lawrence
2016-01-18 15:00         ` Joe Lawrence
2016-01-18 15:43           ` Borislav Petkov
2016-01-18 16:38             ` Joe Lawrence
2016-01-20  3:57           ` Joe Lawrence
2016-01-20  8:26             ` Borislav Petkov
2016-01-22 15:28               ` Joe Lawrence
2016-01-16 21:15     ` [tip:x86/urgent] x86/irq: Call chip-> irq_set_affinity in proper context tip-bot for Thomas Gleixner

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